Synthesis, structures and photoluminescent properties of Cu+ complexes with extended π-systems

Three complexes [Cu2(pz)(pda)2(CH3CN)2](BF4)2 (1), [Cu2(tpphz)(pda)2](BF4)2(CH3CN)4 (2) and [Cu2(bfimbz)(pda)2](BF4)2 (3) (pba = N,N′-bis((diphenylphosphino)methyl)benzenamine, pz = pyrazine, tpphz = tetrapyrido[3,2-a:2′,3′-c:3″,2″-h:2‴,3‴-j]phenazine, bfimbz = 1,4-bis([1,10]-phenanthroline[5,6-d]imidazol-2-yl)-benzene) have been synthesized. They are centrosymmetric dinuclear complexes constructed respectively by bridging imine ligands of pz, tpphz and bfimbz linking two [Cu(pda)] moieties. Ligand pda performs as a terminal bidentate ligand. The solid state luminescence of 1, 2 and 3 are 542, 632 and 584 nm, respectively, while their lifetimes are 86.6, 78.5 and 37.8 μs respectively. The rigid π-conjugated system of the imine ligand could play an active role in intramolecular photoinduced energy or electron transfer between two Cu+ moieties.